diff --git a/electron/main.cts b/electron/main.cts
index cb9e22c..e5b2b4e 100644
--- a/electron/main.cts
+++ b/electron/main.cts
@@ -10,6 +10,7 @@ const { validateRenderRequest } = require('../shared/renderValidation.cjs') as {
 }
 
 const isDev = !app.isPackaged
+const isE2E = process.env.RUWIO_E2E === '1'
 const devServerUrl = process.env.VITE_DEV_SERVER_URL ?? 'http://localhost:5200'
 const devServerOrigin = new URL(devServerUrl).origin
 const appIconPath = isDev
@@ -43,6 +44,12 @@ function sendAppCommand(command: string): void {
   mainWindow.webContents.send('ruwio:menu-command', command)
 }
 
+declare global {
+  // Playwright's Electron runner can evaluate in the main process and call this
+  // env-gated hook without expanding the preload bridge surface.
+  var __ruwioTestMenuCommand: ((command: string) => void) | undefined
+}
+
 function sendRenderProgress(
   target: Electron.WebContents,
   event: { jobId: string; progress: number; done: boolean; error?: string },
@@ -101,9 +108,14 @@ async function runRenderMp4(event: IpcMainInvokeEvent, payload: RenderMp4Payload
     defaultPath: sanitizeMp4Name(payload?.suggestedName),
     filters: [{ name: 'MP4 Video', extensions: ['mp4'] }],
   }
-  const saveResult = window
-    ? await dialog.showSaveDialog(window, saveOptions)
-    : await dialog.showSaveDialog(saveOptions)
+  const e2eSavePath = isE2E
+    ? process.env.RUWIO_E2E_SAVE_PATH || path.join(app.getPath('temp'), saveOptions.defaultPath)
+    : ''
+  const saveResult = e2eSavePath
+    ? { canceled: false, filePath: e2eSavePath }
+    : window
+      ? await dialog.showSaveDialog(window, saveOptions)
+      : await dialog.showSaveDialog(saveOptions)
   if (saveResult.canceled || !saveResult.filePath) return null
 
   const jobId = randomUUID()
@@ -379,6 +391,9 @@ app.setName('RUWIO')
 app.whenReady().then(() => {
   ipcMain.handle('ruwio:render-mp4', handleRenderMp4)
   ipcMain.handle('ruwio:render-cancel', handleRenderCancel)
+  if (isE2E) {
+    globalThis.__ruwioTestMenuCommand = (command: string) => sendAppCommand(command)
+  }
   createMenu()
   createMainWindow()
 
diff --git a/package.json b/package.json
index 971fc0c..3f29cfa 100644
--- a/package.json
+++ b/package.json
@@ -19,7 +19,7 @@
     "test:render-server": "node --test server/server.smoke.test.cjs",
     "test:render-server:e2e": "node --test server/render.e2e.test.cjs",
     "test:render-desktop": "tsc -p tsconfig.electron.json && node scripts/verify-desktop-render.cjs",
-    "test:capture-fidelity": "tsc -p tsconfig.electron.json && electron scripts/verify-capture-fidelity.cjs",
+    "test:capture-fidelity": "tsc -p tsconfig.electron.json && node scripts/run-electron-harness.cjs scripts/verify-capture-fidelity.cjs",
     "stage:ffmpeg": "node scripts/stage-ffmpeg.cjs"
   },
   "dependencies": {
diff --git a/scripts/run-electron-harness.cjs b/scripts/run-electron-harness.cjs
new file mode 100644
index 0000000..1ad5645
--- /dev/null
+++ b/scripts/run-electron-harness.cjs
@@ -0,0 +1,21 @@
+const { spawnSync } = require('node:child_process')
+
+const electron = require('electron')
+const args = process.argv.slice(2)
+
+if (!args.length) {
+  console.error('usage: node scripts/run-electron-harness.cjs <script> [args...]')
+  process.exit(2)
+}
+
+const env = { ...process.env }
+delete env.ELECTRON_RUN_AS_NODE
+env.ELECTRON_DISABLE_SANDBOX = '1'
+
+const res = spawnSync(electron, ['--no-sandbox', ...args], {
+  stdio: 'inherit',
+  env,
+  argv0: electron,
+})
+
+process.exit(res.status ?? 1)
diff --git a/scripts/verify-desktop-render.cjs b/scripts/verify-desktop-render.cjs
index ada3186..70cbf32 100644
--- a/scripts/verify-desktop-render.cjs
+++ b/scripts/verify-desktop-render.cjs
@@ -1,5 +1,5 @@
 // Runs the desktop-render verification harnesses (Phase A/B of
-// electron-rendering-integration-plan_2.md) under Electron and aggregates the
+// 05_electron-rendering-integration-plan_2.md) under Electron and aggregates the
 // results. Each harness exits 0 on PASS, non-zero on FAIL.
 //
 //   npm run test:render-desktop   (compiles electron TS first, then runs this)
@@ -11,6 +11,10 @@ const { spawnSync } = require('node:child_process')
 const path = require('node:path')
 
 const electron = require('electron') // resolves to the electron binary path
+const electronEnv = { ...process.env }
+delete electronEnv.ELECTRON_RUN_AS_NODE
+electronEnv.ELECTRON_DISABLE_SANDBOX = '1'
+
 const harnesses = [
   ['capture', 'verify-capture.cjs', 'hidden-window capturePage produces advancing, non-blank frames (#1/#2)'],
   ['capture-fidelity', 'verify-capture-fidelity.cjs', 'capturePage matches render.html canvas pixels'],
@@ -26,8 +30,9 @@ const harnesses = [
 let failures = 0
 for (const [name, file, desc] of harnesses) {
   process.stdout.write(`\n=== ${name}: ${desc} ===\n`)
-  const res = spawnSync(electron, [path.join(__dirname, file)], {
+  const res = spawnSync(electron, ['--no-sandbox', path.join(__dirname, file)], {
     stdio: ['ignore', 'inherit', 'ignore'], // drop Electron's chatty stderr
+    env: electronEnv,
   })
   if (res.status !== 0) {
     failures += 1